For starting up a motorcycle engine unit, a kickstarter has been used extensively which consits of a lever coupled at one end to the engine unit and having an offset step at the other end, for activation by the thrust of the foot on the step. Usually, the complete kickstarter or its offset step is made pivotally retractable so as not to interfere with the movement of the rider's foot after the engine has been started up.
The kickstarter as heretofore constructed has a serious problem in connection with a pair of footrests fixedly mounted on the opposite sides of the motorcycle to provide supports for the rider's feet during its run. Since one of the footrests is located close to the kickstarter, the rider is likely to strike his foot against the footrest in the act of thrusting down the kickstarter. The result may be either the injury to rider's foot or damage to the footrest.
Another problem with the prior art retractable kickstarter is that vibrations and jolts of the travelling motorcycle can cause the kickstarter to move from its retracted to working position. This is highly objectionable because the kickstarter when in its working position constitutes a serious obstacle to the movement of the rider's foot and can distract his attention, so that in the worst case a traffic accident may result.